graft: start storing new nodes formed in graftstate
This patch starts storing the new nodes formed during the ongoing graft
operation in the graftstate. We need the list of new nodes formed while
implmenting `graft --abort` which will strip out the new nodes.
Differential Revision: https://phab.mercurial-scm.org/D3751
# Blacklist for a full testsuite run with fsmonitor enabled.
# Used by fsmonitor-run-tests.
# The following tests all fail because they either use extensions that conflict
# with fsmonitor, use subrepositories, or don't anticipate the extra file in
# the .hg directory that fsmonitor adds.
#### mainly testing eol extension
test-eol-add.t
test-eol-clone.t
test-eol-hook.t
test-eol-patch.t
test-eol-tag.t
test-eol-update.t
test-eol.t
test-eolfilename.t
#### mainly testing largefiles extension
test-issue3084.t
test-largefiles-cache.t
test-largefiles-misc.t
test-largefiles-small-disk.t
test-largefiles-update.t
test-largefiles-wireproto.t
test-largefiles.t
test-lfconvert.t
#### mainly testing nested repositories
test-nested-repo.t
test-push-warn.t
test-subrepo-deep-nested-change.t
test-subrepo-recursion.t
test-subrepo.t
#### fixing these seems redundant, because these don't focus on
#### operations in the working directory or .hg
test-debugextensions.t
test-extension.t
test-help.t